Health and wellbeing of migrants: the ethnic density effect and other factors

Recent reviews of evidence on the health of migrants in the UK bring out some of the gaps in and limitations of the current research agenda in health. These include a greater focus on some categories of migrants (e.g. asylum seekers, undocumented migrants) and specific areas of health (e.g. mental health, infectious diseases) over others. They also include insufficient emphasis on the impact of migration variables (e.g. country of birth, length of residence, immigration status) compared to ethnic classification.

In relation to the social model of health, an area of interest that has been around for some time, particularly in the United States, but also to some extent in the UK, is the impact of physical locality or place as part of wider determinants of health, and of wellbeing more broadly. However, most current research in this area in the UK, as in much of the mainstream research on health in general, relate to minority ethnic groups, and there is, as yet, insufficient differentiation and analysis according to migration factors.

The ‘ethnic density effect’
Place effect on health is a very complex topic and encompasses many different dimensions. The area in which someone lives (note that the definition and measurement of the boundaries of an area is in itself open to question and is a factor in analysis) relate to health and wellbeing for instance through availability and accessibility of services and resources, physical environmental conditions such as pollution, levels of conflict and crime, quality of housing, and not least, behaviour and attitudes of and interactions with, others living in the area. This last factor has been the focus of a fairly considerable body of research for some time, in particular the effect on health of the extent to which people from minority ethnic groups are likely to live in areas in which there is a concentration of people from similar ethnic/religious/areas of origin backgrounds.

In some research findings, particularly in the US, an ‘ethnic density effect’ has been demonstrated to offset the impact of area-level and individual level deprivation on adult mental health outcomes and infant outcomes such as birthweight, among some minority ethnic groups in urban areas. The causal ‘psychosocial’ pathway here is social capital – support, networks of information, protection from racism and discrimination and so on – that is likely to link people from similar backgrounds living in the same area. The association between ethnic density and health appears to be more variable in studies conducted in the UK.

What can the ‘ethnic density effect’ reveal?
What new insights might be possible from examining the ethnic density hypothesis in relation to the health of migrants, particularly in the UK?

Evidence suggests that there are both differences and similarities in the relationship of recent migrants to their local areas of residence, compared to that of more established minority ethnic communities. In some urban areas of high same religious/ethnic density, living among longer-established people from similar areas of origin and benefiting from their support, information and advice, is important to a sense of security and wellbeing among recent arrivals and contributes to their integration as newcomers in the wider society.

Other research has shown that the inverse association between perceptions of racism and good health outcomes decreases as either own ethnic density or overall ethnic minority density increases for some of the main ethnic minority categories in the UK – Caribbean, Indian, Pakistani and Bangladeshi- suggesting that ethnic density may have a buffer effect on the negative impact of racism on health. It could be hypothesised that such associations may be greater for recent migrants, and there may be changes according to length of residence.

Growing migrant diversity raises further questions
The growing diversity of migrant categories and changing settlement patterns also need to be taken into account in understanding the effects of place on health.

Do people from countries of origin that do not contribute to the main large ethnic minority categories in the UK demonstrate a different relationship between ethnic density and health given that they may be living in areas where own ethnic density is lower (although this would depend on the scales of geography studied)?

Apart from important socio-demographic differences between migrants, what part is played by other ‘cultural’ density-related characteristics such as religion or legal settlement status/nationality or level of transnational engagement and identification?

More research is needed on the relationship between the recent settlement of migrants in local areas of very low ethnic minority densities, and the health and wellbeing of these migrant categories, for instance ‘Other White’ migrants from new European Union countries.

All migration variables needed to fully understand health
Much existing research on ethnic density has been based on quantitative analysis of the relationship between a range of health determinants and various health outcomes of a population or populations in question. This approach potentially allows for rigorous examination of the complex pathways to health and wellbeing, by disentangling the effects of individual characteristics from area characteristics, and socio-economic characteristics from ‘cultural’ characteristics, through multilevel analysis.

It has not been common to routinely examine the contribution of migration variables such as country of birth of individuals and length of residence in the UK in such analyses, even where they exist. However, it is imperative to do so, to get an understanding of all possible factors that affect health outcomes. A recent analysis of health outcomes of migrant mothers in a large UK population based dataset showed that ethnicity is a more important predictor of smoking and alcohol consumption than is length of residence in the UK after adjustment for socio-demographic factors including overall minority ethnic density at ward level. This kind of finding has implications more broadly for critically examining the ‘healthy migrant effect’ and ‘acculturation’ theses – that is the idea of selectivity in migration of healthier people which is associated with positive health outcomes which in turn change/deteriorate over time as migrants adopt health behaviours characteristic of receiving society populations.